Establishment And Application Of Molecular Biological Detection Methods For Genetically Modified Food

With the continuous development of genetically modified technology and the growing area of genetically modified crops(GMC),the detection technology and detection methods of GMF have become the focus of attention of experts and scholars.In this study,the results showed that the content and purity of DNA extracted by CTAB method were higher than those extracted by the other two methods when soybean and its processed products were used as materials,which was suitable for the DNA extraction of GMF.In this study,a qualitative PCR detection method for pCaMV35S,tNOS,t35S,pNOS,pFMV35S,Hpt,CP4-EPSPS,Cry1A.105,Cry2Ab2 exogenous elements in GMC was established,of which the relative limit of detection was 0.1%~0.5%.A SYBR Green I qualitative PCR method for pCaMV35S,tNOS,t35S,pFMV35S,Vip3Aa20,Cry1A.105 and Cry2Ab2 exogenous elements in GMC was established,of which the limit of detection was18~44 copies.The event-specific TaqMan probe quantitative PCR detection method was established for GM maize MON89034,GM soybean MON89788 and GM maize GA21,and whose standard curves were drawn as well.The limit of quantitative of MON89034 event-specific detection method was 45 copies,of which the standard curve has high PCR efficiency(99.6%) and good linearity(R~2>0.99).The limit of quantitative of MON89788 event-specific detection method was 50 copies,whose standard curve has high PCR efficiency(94.5%)and linearity(R~2>0.99).And the limit of quantitative of GA21event-specific detection method was 2 copies.The PCR efficiency and R~2 value of the standard curve of GA21 was 104.8% and more than 0.98.Both the standard deviation(SD)and the relative standard deviation(RSD) of them are within the allowable range.In this study,pCaMV35S,tNOS,pFMV35S and CP4-EPSPS exogenous elements in GMC were screened by the qualitative PCR detection method in processed products of corn and soybean on the market.In 9 different food samples,the tNOS and CP4-EPSPS GM components were detected in tofu,which was confirmed by sequencing.In this study,based on different detection strategies,PCR detection methods of GMF for different target sequences were developed,and the application and verification of the actual samples were carried out.The research results provided the laboratory basis for the molecular biological detection methods of GMF.